如果人們只是向前忘了顧後，恐怕疑惑生焉？！
分明清楚定義那個輸入訊號 
︰
總不會因為例子中改叫作 
而有不同吧！？
奈何『時間軸』竟受 
影響耶？？
倘再考之以 
的關聯，當能領會『預設之旨』乎！！
無怪 librosa 有這麼多
Time and frequency conversion
frames_to_samples(frames[, hop_length, n_fft]) |
Converts frame indices to audio sample indices |
frames_to_time(frames[, sr, hop_length, n_fft]) |
Converts frame counts to time (seconds) |
samples_to_frames(samples[, hop_length, n_fft]) |
Converts sample indices into STFT frames. |
samples_to_time(samples[, sr]) |
Convert sample indices to time (in seconds). |
time_to_frames(times[, sr, hop_length, n_fft]) |
Converts time stamps into STFT frames. |
time_to_samples(times[, sr]) |
Convert timestamps (in seconds) to sample indices. |
hz_to_note(frequencies, **kwargs) |
Convert one or more frequencies (in Hz) to the nearest note names. |
hz_to_midi(frequencies) |
Get the closest MIDI note number(s) for given frequencies |
midi_to_hz(notes) |
Get the frequency (Hz) of MIDI note(s) |
midi_to_note(midi[, octave, cents]) |
Convert one or more MIDI numbers to note strings. |
note_to_hz(note, **kwargs) |
Convert one or more note names to frequency (Hz) |
note_to_midi(note[, round_midi]) |
Convert one or more spelled notes to MIDI number(s). |
hz_to_mel(frequencies[, htk]) |
Convert Hz to Mels |
hz_to_octs(frequencies[, A440]) |
Convert frequencies (Hz) to (fractional) octave numbers. |
mel_to_hz(mels[, htk]) |
Convert mel bin numbers to frequencies |
octs_to_hz(octs[, A440]) |
Convert octaves numbers to frequencies. |
fft_frequencies([sr, n_fft]) |
Alternative implementation of np.fft.fftfreqs |
cqt_frequencies(n_bins, fmin[, …]) |
Compute the center frequencies of Constant-Q bins. |
mel_frequencies([n_mels, fmin, fmax, htk]) |
Compute the center frequencies of mel bands. |
tempo_frequencies(n_bins[, hop_length, sr]) |
Compute the frequencies (in beats-per-minute) corresponding to an onset auto-correlation or tempogram matrix. |
換算函式呦☆
請循其本也◎
※ 參考
